The present invention generally relates to an adjustable pillow used to support a person's head and neck in an optimal posture during sleep or when lying supine. More specifically, the invention is a multi-density multi.layer cervical pillow having adjustable elevation and inclination support to facilitate an anatomically neutral position of the head and neck for a wide range of users.
Research shows that sleep comfort is directly related to sleep posture. Entire industries have developed around the manufacture of alternative bed constructions, each one offering various features directed to achieving a good night's sleep. Posture beds, water beds, spring beds, futons and inclining beds, to name only a few, all offer unique characteristics. The user can select the type of bed construction which best complements their sleep preferences and anatomical build. Most people fail to understand, however, that a pillow can affect sleep comfort as much as, if not more than, the bed.
Unfortunately, most conventional pillows do not offer proper anatomical support and alignment of the head and cervical spine (neck) nor do they offer any adjustability to tailor the support to the particular anatomical characteristics of the user or variations of the sleeping surface. Although one can select a pillow from a wide range of firmnesses and materials, generally pillows are only offered as a one-size-fits-all configuration. The fact is that the build of a specialized athlete, such as a football or rugby player, is quite different than a child or a senior citizen. Shoulder width, head size and neck size can vary enormously between individuals. A pillow which provides proper support and height to a head of a small child sleeping on her side would most certainly not provide proper support or height for a muscular male athlete sleeping on his side, with broad shoulder width elevating the head a greater distance from the sleeping surface. Likewise, some individuals like to sleep on their sides while others enjoy sleeping on their backs or fronts. Each of these positions place the head in a different position and at a different height from the sleeping surface. People accommodate by adopting various sleep habits such as extending an arm under the pillow, doubling up a pillow or using multiple pillows in an effort to achieve comfort, proper pillow support I0 and proper head height. These abnormal sleep postures are the most common cause of neck pain upon awakening and, albeit less frequently, a cause of headache or jaw pain.
The human cervical spine is generally curved, not straight. This curve, called the lordotic curve, is caused by the trapezoid shape structure of the vertebrae in our necks. The cervical spine is composed of seven vertebrae and five moveable joints producing a gentle curve. The seven vertebrae are interconnected to provide protection for the spine while allowing a relatively large range of movement of the head. Nerves extend between vertebrae to connect the spinal cord to sensory and motor nerves throughout our body. As people age, degenerative changes tend to cause the vertebrae to compress together causing arthritis and other ailments. Neck flexion and/or extension injuries, such as "whiplash", cause tissue swelling which can pinch nerves between vertebrae and cause pain. During sleep, abnormal sleep posture resulting in prolonged lack of support or improper support of the neck and head can aggravate these existing conditions or be the primary cause of discomfort.
Improper sleep postures themselves can cause excessive flexion, or rotation or extension of the relatively heavy head and fragile cervical spine during sleep. These sleep postures, including "chin on chest" positions, may lead to damage, twisting or irritation of the cervical spine causing neck pain, neck stiffness or headaches noticeable upon awakening even with people otherwise enjoying excellent health. It has been estimated that up to 70% of headaches originate in the area of the neck and shoulders from a variety of causes, including improper sleep habits.
Frequently, conventional pillows are either too thick and high, thereby over flexing the cervical spine of the user and causing "chin on chest" posture, or too soft and low, thereby bottoming out and leaving the head and neck without either vertical or lateral support. Conventional pillows offer no structural adjustability to compensate for these support deficiencies.
In recognition of these inadequacies, specially shaped pillows have been designed to provide proper head and neck support during specialized medical procedures. One such pillow is described in U.S. Pat. No. 4,320,543, which discloses a medical pillow having a central depression area to provide vertical and lateral support for the head and neck. The purpose of this pillow is to provide proper alignment of the patient,s airway from teeth to lungs to promote circulation and stabilize the head during surgical procedures which require mechanical ventilation of comatose patients. This pillow, however, provides a structure capable of only two different supporting elevations selectable by rotating the pillow at 180.degree. angles. This feature is insufficient to provide meaningful support and comfort options required by a wide range of user anatomies and sleep preferences of the general public during normal sleep.